What should we compare? Only the score? Let me explain.
One can expect a test done in 800x600x16 to get a higher score than the same test done in 1920x1080x32. Is it the case? If yes, it means that people can make their score look like the best just because they selected a low resolution. So results are bogus.

Blindly comparing the scores is always going to get you into trouble. We have graphics cards in different machines, with different CPU clock speeds, and different driver and graphics libraries.

Regarding 16-bit and 32-bit screens, the scores are scaled by the bit-depth in an attempt to reduce the effect of the screen depth on the score (as is detailed here. Nevertheless, it still isn't a good idea to compare them directly, which is one of the reasons why the screen-mode is shown on the GfxBench2D home page.